1. Field of the Invention
This invention relates to pre-sharpened cutting tips for a saw plate which can be accurately brazed onto the saw plate. The configuration of the saw tips also provides relatively low friction between the saw blade and workpiece.
2. Description of the Prior Art
Cutting tips, generally of tungsten carbide, are commonly brazed onto the working edges of a saw plate to increase the useful life of the saw blade. Generally, the tips are formed in a die and then sintered under heat to bond the ingredients together. Since a certain amount of shrinkage occurs during sintering, the carbide tips vary in all dimensions and their edges are not sharp. Die-forming is equally ineffective since this material does not readily lend itself to the creation of sharp edges. The edges of the cutting tips have a tendency to be slightly rounded or chamfered, and must be ground to produce an edge sufficiently keen to sever the wood fibers or other materials to be cut by the saw blade. The grinding operation is generally performed after the tips have been brazed onto the saw plate. During the grinding operation, all exposed surfaces of the tip are ground. The sides are ground with a slight taper from front face to back, as well as a taper from top to bottom. This geometry provides clearance so that the friction between the tip and the workpiece is relatively low, to prevent the saw from binding in the cut.
It is both difficult and time-consuming to sharpen the tips after they are brazed onto the saw plate since the grinding machinery must be set up for each face of each tip. Although the tips may be sharpened prior to brazing them onto the saw plate, the tapered sides of the tips make it extremely difficult to properly install them. The taper causes the tip to locate incorrectly with reference to the parallel sides of the saw plate. Thus, as a practical matter, conventional tips are sharpened after brazing onto the saw plate.
Cutting tips having non-tapered, i.e., parallel, sides may be ground prior to being brazed onto a saw plate; however, the non-tapered tips tend to bind during cutting operations and require increased power to rotate the saw blade.